POSITION DETECTING DEVICE
20180143710 ยท 2018-05-24
Inventors
Cpc classification
G01D9/10
PHYSICS
G06F3/0488
PHYSICS
G06F3/04182
PHYSICS
G06F3/0446
PHYSICS
G06F3/0448
PHYSICS
G06F3/0442
PHYSICS
G06F3/04164
PHYSICS
G06F3/04166
PHYSICS
International classification
G01D9/10
PHYSICS
G06F3/0488
PHYSICS
Abstract
The invention allows size reduction of a sensor of a position detecting device of a capacitive system, which detects a position indicated by an indicator. The sensor has plural electrode conductors that are disposed adjacent to each other and are configured to receive a signal from the indicator on a first surface of a substrate having the first surface and a second surface opposed to each other. The position detecting device includes a signal processing circuit including a differential amplifier circuit that calculates a difference between signals from at least two of the plural electrode conductors. Plural connecting lines are formed on the second surface of the substrate. The plural connecting lines each have one end connected to one of the plural electrode conductors disposed on the first surface by a through-hole or a via formed through the substrate, and the other end connected to a line-concentrated part.
Claims
1. A device for detecting a position of an object in a detection area, comprising: a panel providing a horizontal surface; an electrode layer arranged underneath the panel and formed of a plurality of block-shaped conductor patterns laid within the detection area; a wiring layer arranged underneath the electrode layer and formed of a plurality of routing lines extending respectively from the plurality of block-shaped conductor patterns within the detection area toward a collection area outside the detection area; vias that respectively connect the plurality of block-shaped conductor patterns within the detection area to the plurality of routing lines in a direction perpendicular to the horizontal surface; and circuitry which is coupled to the collection area and which, in operation, detects the position of the object in the detection area based on electric charges respectively induced in the plurality of block-shaped conductor patterns.
2. The device of claim 1, wherein each of the vias is positioned within an area of each of the plurality of block-shaped conductor patterns.
3. The device of claim 1, wherein the routing lines extend in a direction perpendicular to a peripheral edge of the detection area.
4. The device of claim 3, wherein the routing lines are grouped into bundles.
5. The device of claim 1, wherein the object is an active pen configured to transmit electric signals, and the plurality of block-shaped conductor patterns laid in the electrode layer constitute a shield for the routing lines arranged in the wiring layer underneath the electrode layer.
6. The device of claim 1, wherein first sub-sets of conductor patterns including the plurality of block-shaped conductor patterns are connected along a first direction to form a first set of elongated electrodes each extending in the first direction, and the routing lines extend in a second direction different from the first direction.
7. The device of claim 6, wherein second sub-sets of conductor patterns are connected along the second direction, via connectors in the wiring layer underneath the electrode layer, to form a second set of elongated electrodes each extending in the second direction.
8. The device of claim 1, comprising a display, wherein the panel is arranged underneath the display.
9. A device for detecting a position of a position indicator based on an electric signal transmitted from the position indicator, the device comprising: a panel providing a surface; first electrodes connected along a first direction within the panel; second electrodes connected along a second direction different from the first direction within the panel; circuitry which is coupled to the first and second electrodes and which, in operation, detects the position of the position indicator based on a distribution of reception levels of the electric signal transmitted from the position indicator at defined ones of the first and second electrodes; and floating electrodes that are arranged among the first and second electrodes and are not electrically connected to any of the first and second electrodes.
10. The device of claim 9, wherein the floating electrodes smooth out a change in the reception levels of the electric signal transmitted from the position indicator detected at the defined ones of the first and second electrodes.
11. The device of claim 10, wherein the floating electrode suppresses the reception level at the electrode closest to the position indicator to thereby decrease a difference in the reception levels at the electrode closest to the position indicator and the electrode second-closest to the position indicator.
12. The device of claim 10, wherein the floating electrode increases the reception level at the electrode that is second-closest to the position indicator.
13. The device of claim 10, wherein the floating electrode is positioned within an area defined by an outer periphery of the first electrode.
14. The device of claim 10, wherein the floating electrode is positioned between the first electrode and the second electrode that are adjacent to each other.
Description
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0024]
[0025]
[0026]
[0027]
[0028]
[0029]
[0030]
[0031]
[0032]
[0033]
[0034]
DETAILED DESCRIPTION
First Embodiment
[0035]
[0036] The sensor 10 includes a first electrode conductor group 12 and a second electrode conductor group 13 on a substrate 11 composed of, for example, resin. In this example, the substrate 11 is a flat plate having a rectangular shape and has a front surface 11a as a first surface and a back surface 11b (see
[0037] The first electrode conductor group 12 is obtained by juxtaposing plural first electrode conductors 12Y.sub.1, 12Y, . . . , 12Y.sub.m, extending along the horizontal direction (X-axis direction) and separated by predetermined intervals such that they are not electrically connected to each other. The second electrode conductor group 13 is obtained by juxtaposing plural second electrode conductors 13X.sub.1, 13X.sub.2, . . . , 13X.sub.n, extending along a direction that intersects the first electrode conductors 12Y.sub.1 to 12Y.sub.m (the vertical direction (Y-axis direction) orthogonal to the first electrode conductors 12Y.sub.1 to 12Y.sub.m in this example) and separated by predetermined intervals.
[0038] The first electrode conductors 12Y.sub.1 to 12Y.sub.m and the second electrode conductors 13X.sub.1 to 13X.sub.n are both formed on the front surface 11a of the substrate 11. In the first embodiment, as will be described later, all of the first electrode conductors 12Y.sub.1 to 12Y.sub.m, including the intersecting parts (see 32Y in
[0039] Furthermore, in the first embodiment, projecting parts 14A and 15A, which form a line-concentrated part 14 for the second electrode conductor group 13 and a line-concentrated part 15 for the first electrode conductor group 12, respectively, are formed on one end side of the rectangular substrate 11 in the Y-axis direction. The projecting parts 14A and 15A, at which the line-concentrated parts 14 and 15 are formed, serve as connectors for connecting to the signal processing circuit 20.
[0040] The line-concentrated part 14 for the second electrode conductor group 13 is provided on the side of the front surface 11a of the substrate 11 and the line-concentrated part 15 for the first electrode conductor group 12 is provided on the back surface side of the substrate 11. Furthermore, the line-concentrated part 15 for the first electrode conductor group 12 is electrically connected to each of the first electrode conductors 12Y.sub.1 to 12Y.sub.m via the through-holes.
[0041] As described above, the position detecting device of the first embodiment forms a position detecting device of a capacitive system that includes the sensor in which the first electrode conductor group 12 and the second electrode conductor group 13 are so disposed that the extension direction of the first electrode conductor group 12 is orthogonal to the extension direction of the second electrode conductor group 13. Furthermore, the position detecting device detects a position indicated by the indicating pen 40 based on change in the capacitance at the intersections of the first electrode conductors 12Y.sub.1 to 12Y.sub.m and the second electrode conductors 13X.sub.1 to 13X.sub.n.
[0042] The indicating pen 40 internally includes an oscillator circuit 41. The oscillator circuit 41 is a circuit for generating a signal with a frequency of, for example, 1.8 MHz. The indicating pen 40 transmits the signal generated by the oscillator circuit 41 from a pen tip part 42 externally. The sensor 10 receives the signals transmitted from the indicating pen 40 by the first electrode conductor group 12 and the second electrode conductor group 13. Then, the signals received by the first electrode conductor group 12 and the second electrode conductor group 13 are each supplied to the signal processing circuit 20.
[0043] The signal processing circuit 20 is a circuit for executing predetermined signal processing on the signal received by the sensor 10. The signal processing circuit 20 includes selecting circuits 21 and 22, differential amplifier circuits 23 and 24, and a control circuit 25.
[0044] The signals received by the sensor 10 are inputted in to the control circuit 25 via the selecting circuits 21 and 22 and the differential amplifier circuits 23 and 24 in the signal processing circuit 20. The control circuit 25 checks the level of the received signals at the respective electrode conductors 12Y.sub.1 to 12Y.sub.m of the first electrode conductor group 12 and the respective electrode conductors 13X.sub.1 to 13X.sub.n of the second electrode conductor group 13, and detects that the indicating pen 40 exists over an electrode conductor where the level of the 1.8-MHz signal is a high level.
[0045] Each of the first electrode conductors 12Y.sub.1 to 12Y.sub.m is connected to the selecting circuit 22 via the line-concentrated part 15. Similarly, each of the second electrode conductors 13X.sub.1 to 13X.sub.n is connected to the selecting circuit 21 via the line-concentrated part 14. The selecting circuit 21 and the selecting circuit 22 are connected to the differential amplifier circuits 23 and 24, respectively.
[0046] The selecting circuit 21 includes, for example, a microprocessor. The selecting circuit 21 selects an electrode conductor to be connected to the positive-side input terminal (non-inverting input terminal) of the differential amplifier circuit 23 and an electrode conductor to be connected to the negative-side input terminal (inverting input terminal) of the differential amplifier circuit 23 among the second electrode conductors 13X.sub.1 to 13X.sub.n in response to selection control from the control circuit 25. Similarly, the selecting circuit 22 selects an electrode conductor to be connected to the positive-side input terminal of the differential amplifier circuit 24 and an electrode conductor to be connected to the negative-side input terminal of the differential amplifier circuit 24 among the first electrode conductors 12Y.sub.1 to 12Y.sub.m in response to selection control from the control circuit 25.
[0047] The differential amplifier circuit 23 and the differential amplifier circuit 24 each perform a difference calculation between an input signal to the positive-side input terminal and an input signal to the negative-side input terminal. The differential amplifier circuit 23 and the differential amplifier circuit 24 then output, to the control circuit 25, output signals according to the intensity of signals received by the first electrode conductors 12Y.sub.1 to 12Y.sub.m and the second electrode conductors 13X.sub.1 to 13X.sub.n, respectively, with noise entering the first electrode conductors 12Y.sub.1 to 12Y.sub.m and the second electrode conductors 13X.sub.1 to 13X.sub.n being cancelled. In this embodiment, although not shown in
[0048] The control circuit 25 detects the position coordinate of the X-axis direction of a position indicated by the indicating pen 40 on the sensor 10 from the intensity of the output signal of the differential amplifier circuit 23 and the second electrode conductors selected by the selecting circuit 21 among the second electrode conductors 13X.sub.1 to 13X.sub.n. Furthermore, the control circuit 25 detects the position coordinate of the Y-axis direction of a position indicated by the indicating pen 40 on the sensor 10 from the intensity of the output signal of the differential amplifier circuit 24 and the first electrode conductors selected by the selecting circuit 22 among the first electrode conductors 12Y.sub.1 to 12Y.sub.m. In this manner, the control circuit 25 detects the coordinates of the position indicated by the indicating pen 40.
[0049] A position indicated by the indicating pen 40 may be roughly detected by all of the electrode conductors of the sensor 10 such that, by the selecting circuit 21 and the selecting circuit 22, plural electrode conductors are connected to each of the positive-side input terminals and the negative-side input terminals of the differential amplifier circuit 23 and the differential amplifier circuit 24. In this embodiment, after the rough position of the indicating pen 40 is detected, detailed detection of the position indicated by the indicating pen 40 is carried out by plural first electrode conductors and second electrode conductors near the detected position. In the detailed detection of the indicated position, the selecting circuit 21 and the selecting circuit 22 are controlled by the control circuit 25 to select one each electrode conductor to be connected to the positive-side input terminals and the negative-side input terminals of the differential amplifier circuit 23 and the differential amplifier circuit 24.
[Configuration Example of Sensor 10]
[0050] Next, the configuration of the conductor patterns including the first electrode conductor group 12, the second electrode conductor group 13, and the line-concentrated parts 14 and 15 formed in the sensor 10 will be described with reference to
[0051] As shown in
[0052] As shown in
[0053] As shown in
[0054] For the plural conductor patterns 31 other than the plural conductor patterns 31Y configuring the first electrode conductors 12Y.sub.1 to 12Y.sub.m (hereinafter, referred to as the conductor patterns 31X), the conductor patterns 31X, which are in a straight line along the Y-axis direction, are electrically connected to each other, as described below, to form the second electrode conductors 13X.sub.1 to 13X.sub.n.
[0055] As shown in
[0056] Furthermore, as shown in
[0057] Moreover, as shown in
[0058] On the other hand, as described below in reference to
[0059] Specifically, as shown in
[0060] Because the second connecting parts 34X of the second electrode conductors 13X.sub.1 to 13X.sub.n are provided on the back surface 11b of the substrate 11, the through-holes 37Y overlapping with the conductor patterns 31Y adjacent in the Y-axis direction are slightly offset from the second connecting parts 34X and from each other in the X-axis direction. The purpose of this is to shorten the lengths of the connecting lines 38Y.sub.1 to 38Y.sub.m while preventing them from overlapping with the second connecting parts 34X.
[0061] As shown in
[0062] By setting the extension direction of the second connecting parts 34X parallel to the extension direction of the connecting lines 38Y.sub.1 to 38Y.sub.m in this manner, the connecting lines 38Y.sub.1 to 38Y.sub.m can be formed close to the second connecting parts 34X. Therefore, the distance between two electrode conductors connected to the non-inverting input terminal and the inverting input terminal of the differential amplifier circuit 23 can be shortened and enhancement in the noise resistance obtained by the differential amplification can be achieved. Moreover, because the distances among the connecting lines 38Y.sub.1 to 38.sub.m can be set shorter, the lowering of the density of the connecting lines 38Y.sub.1 to 38.sub.m can be minimized. The connecting lines 35X.sub.1 to 35X.sub.n for the second electrode conductors 13X.sub.1 to 13X.sub.n are formed in the interconnect area 36 on the side of the front surface 11a of the substrate 11.
[0063] Therefore, according to this embodiment, the interconnect area of the connecting lines can be smaller than in the related arts. Thus, the size of the substrate can be reduced, which can prevent the lowering of convenience and design property.
[0064] Furthermore, because the connecting lines 35X.sub.1 to 35X.sub.n for the second electrode conductors 13X.sub.1 to 13X.sub.n are formed in the interconnect area, a detection result of a position indicated by the indicating pen can be obtained with the same accuracy as that in the related arts regarding received signals from the second electrode conductors 13X.sub.1 to 13X.sub.n.
[0065] The connecting lines 38Y.sub.1 to 38Y.sub.m for the first electrode conductors 12Y.sub.1 to 12Y.sub.m are formed on the side of the back surface 11b of the substrate 11 to overlap with the conductor patterns 31 (31X and 31Y), which form the first electrode conductor group 12 and the second electrode conductor group 13 on the side of the front surface 11a of the substrate 11. Therefore, the influence of a jump of a transmitted signal from the indicating pen 40 to the connecting lines 38Y.sub.1 to 38.sub.m is an issue.
[0066] However, the connecting lines 38Y.sub.1 to 38.sub.m are electrostatically shielded by the plural conductor patterns 31 (31X and 31Y) provided on the front surface 11a of the substrate 11, and reception of a transmitted signal from the indicating pen 40 by the connecting lines 38Y.sub.1 to 38.sub.m is prevented or alleviated. Furthermore, the connecting lines 38Y.sub.1 to 38.sub.m are disposed close to each other. Therefore, even when a signal or noise is superimposed on these connecting lines 38Y.sub.1 to 38Y.sub.m, the signal or noise is superimposed on connecting lines adjacent to each other in a similar manner. This allows the signal or noise superimposed on the connecting lines 38Y.sub.1 to 38Y.sub.m to be removed by performing a difference calculation on signals from plural electrode conductors in the differential amplifier circuit of the signal processing circuit.
[0067] Furthermore, the connecting lines 38Y.sub.1 to 38Y.sub.m for the first electrode conductors 12Y.sub.1 to 12Y.sub.m are formed on the side of the back surface 11b of the substrate 11 and extend along the Y-axis direction intersecting (orthogonal to) the X-axis direction, along which the first electrode conductors 12Y.sub.1 to 12Y.sub.m extend. Thus, it is easy to form the connecting lines 38Y.sub.1 to 38Y.sub.m in parallel and close to each other on the side of the back surface 11b of the substrate 11. Moreover, for the second electrode conductors 13X.sub.1 to 13X.sub.n, whose extension direction is the direction along which the connecting lines 38Y.sub.1 to 38Y.sub.m extend, the conductor patterns 31X are connected to each other by the second connecting parts 34X along the Y-axis direction via through-holes on the side of the back surface 11b of the substrate 11. Thus, the connecting lines 38Y.sub.1 to 38Y.sub.m are parallel to the second connecting parts 34X. Therefore, even when the connecting lines 38Y.sub.1 to 38Y.sub.m straddle the second connecting parts 34X, the distance between the connecting lines 38Y.sub.1 to 38Y.sub.m straddling the second connecting parts 34X can be short and the lowering of the density of the connecting lines 38Y.sub.1 to 38Y.sub.m can be suppressed to a minimum.
Second Embodiment
[0068] A second embodiment is a modification example of the first embodiment. A sensor 10B in the second embodiment is different from the sensor 10 in the first embodiment in the following points. Specifically, the respective conductor patterns 31X configuring the second electrode conductors 13X.sub.1 to 13X.sub.n formed on the front surface 11a of the substrate 11 of the sensor 10B of the second embodiment are connected to each other on the front surface Ila of the substrate 11. Furthermore, the respective conductor patterns 31Y configuring the first electrode conductors 12Y.sub.1 to 12Y.sub.m are connected to each other on the side of the back surface 11b of the substrate 11.
[0069]
[0070] In the second embodiment, third connecting parts 32X, which electrically connect the adjacent conductor patterns 31 to each other, are formed between respective two of the plural conductor patterns 31 that are lined on a straight line. Multiple such lines are formed and arranged from the upper end toward the lower end in the Y-axis direction, as viewed from the side of the front surface 11a of the substrate 11, among the plural conductor patterns 31 on each column lined on a straight line along the Y-axis direction. The third connecting parts 32X are formed to extend along the Y-axis direction on the front surface 11a of the substrate 11. The conductor patterns 31X adjacent in the Y-axis direction are electrically connected to each other by the third connecting parts 32X, so that the second electrode conductors 13X, to 13X.sub.n shown in
[0071] The plural conductor patterns 31Y, other than the plural conductor patterns 31X configuring the second electrode conductors 13X.sub.1 to 13X.sub.n, included in a straight line along the X-axis direction are electrically connected to each other as described below to form each of the first electrode conductors 12Y.sub.1 to 12Y.sub.m (in
[0072] Specifically, as shown in
[0073] As shown in
[0074] As shown in
[0075] On the other hand, as shown in
[0076] Specifically, as shown in
[0077] Furthermore, as shown in
[0078] Also in the second embodiment, because the fourth connecting parts 34Y are provided on the back surface of the substrate 11, the through-holes 37X overlapping with the conductor patterns 31X adjacent in the X-axis direction are slightly offset from the fourth connection parts 34Y and from each other in the Y-axis direction. The purpose of this is to shorten the lengths of the connecting lines 38X while preventing them from overlapping with the fourth connecting parts 34Y.
[0079] One end of each of the connecting lines 38X is electrically connected to a corresponding one of the second electrode conductors 13X.sub.1 to 13X.sub.n via the through-hole 37X. Each connecting line 38X is formed to linearly extend along the X-axis direction at least in the area opposed to the conductor patterns 31. The other end of each of the connecting lines 38X is formed to be led to the line-concentrated part 15 of the projecting part 15B provided at the left end of the substrate 11 in the X-axis direction.
[0080] In this case, whereas the extension direction of the second electrode conductors 13X.sub.1 to 13X.sub.n is the Y-axis direction, the extension direction of each of the plural connecting lines 38X is the X-axis direction. This allows the parts linearly extending along the X-axis direction in the connecting lines 38X to be disposed in parallel and close to each other.
[0081] As above, in the second embodiment, the connecting lines 38X can be formed close to the fourth connecting parts 34Y because the extension direction of the fourth connecting parts 34Y is parallel to the extension direction of the connecting lines 38X. Therefore, the distance between two electrode conductors connected to the non-inverting input terminal and the inverting input terminal of the differential amplifier circuit 23 can be shortened and enhancement in the noise resistance obtained by the differential amplification can be achieved. Moreover, because the distances among the connecting lines 38X can be set shorter, the lowering of the density of the connecting lines 38X can be minimized.
[0082] Furthermore, in the second embodiment, only the connecting of the conductor patterns 31 (31Y and 31X) regarding the first electrode conductors 12Y.sub.1 to 12Y.sub.m and the second electrode conductors 13X.sub.1 to 13X.sub.n, and the lead-out direction of the connecting lines are different from the first embodiment as described above. The same operation and effect as those of the above-described first embodiment are achieved.
Third Embodiment
[0083] In the above-described first and second embodiments, the cases in which the connecting lines of either one of the first electrode conductors 12Y.sub.1 to 12Y.sub.m and the second electrode conductors 13X.sub.1 to 13X.sub.n are formed on the back surface of the substrate 11 are exemplified. However, the connecting lines of both the first electrode conductors 12Y.sub.1 to 12Y.sub.m and the second electrode conductors 13X.sub.1 to 13X.sub.n may be formed on the back surface of the substrate 11 and be made opposed to the conductor patterns 31 (31Y and 31X) configuring the first electrode conductors 12Y.sub.1 to 12Y.sub.m and the second electrode conductors 13X.sub.1 to 13X.sub.n. A third embodiment is an example of this case.
[0084]
[0085] As shown in
[0086] In the first substrate 11D, instead of the through-holes 37X in the second embodiment, vias 37XD that penetrate both the first and second substrates 11D and 11E when the first and second substrates 11D and 11E are attached to each other are formed. Furthermore, in the first substrate 11D, similar to the through-holes 33Y in the second embodiment, vias 33YB for electrically connecting the conductor patterns 31Y adjacent in the X-axis direction to each other (via the fourth connecting parts 34Y) on a back surface 11Db of the first substrate 11D are formed. The vias 37XD and the vias 33YB are formed at the same positions where the through-holes 37X and 33Y in the second embodiment are formed.
[0087] As shown in
[0088] In the second substrate 11E, the vias 37XD and plural connecting lines 38XD (on a back surface 11Eb of the second substrate 11E, as described later) and 38YD (on a front surface 11Ea of the second substrate 11E, as described later) are formed. As shown in
[0089] As shown in
[0090] Furthermore, as shown in
[0091] In this case, the plural connecting lines 38YD extend along the X-axis direction in parallel with each other as shown in
[Modification Examples of Shape of Conductor Pattern 31]
FIRST EXAMPLE
[0092] In the above-described embodiments, the cases in which the conductor patterns 31 (31X and 31Y) are formed into a diamond shape, particularly a square shape, are exemplified. However, the shape of the conductor patterns 31 (31X and 31Y) may be any shape as long as the first electrode conductors 12Y.sub.1 to 12Y.sub.m are the same as the second electrode conductors 13X.sub.1 to 13X.sub.n in the detection sensitivity of the indicator and the shape allows the whole of the front surface 11a of the substrate 11 to be covered as much as possible.
[0093]
[0094] The first electrode conductors 12Y.sub.1 to 12Y.sub.m (12Y.sub.i, 12Y.sub.i+1, and 12Y.sub.i+2 are shown in
[0095] In the case of the conductor patterns 311 (311Y and 311X) shown in the first example, the adjacent conductor patterns 311 (311Y and 311X) partially enter each other's conductor pattern areas and are interlaced with each other as shown in
SECOND EXAMPLE
[0096]
[0097] The first electrode conductors 12Y.sub.1 to 12Y.sub.m (12Y.sub.i, 12Y.sub.i+1, and 12Y.sub.i+2 are shown in
[0098] According to the second example, the square part 312e formed in the electrically floating state does not contribute to reception of a transmitted signal from an indicating pen. Therefore, the second highest signal level further increases at the electrode conductor that receives a signal from the indicating pen 40 (see
THIRD EXAMPLE
[0099]
[0100] According to the third example, because the square part 313g is formed to enter the adjacent conductor pattern 313, the detection sensitivity of the indicating pen can be enhanced similar to the conductor patterns 311 and 312 in the first and second examples, respectively.
Other Embodiments or Modification Examples
[0101] The above embodiments are described by exemplifying the cases of application thereof to a sensor of a system to detect a position indicated by the indicating pen 40 based on change in the capacitance at the intersections of the first electrode conductors extending along the X-axis direction and the second electrode conductors extending along the Y-axis direction. However, it is also possible to apply the invention to a sensor in which electrode conductors are arranged along only one of the X-axis direction and the Y-axis direction.
[0102] By forming the conductor patterns to configure the first electrode conductors and the second electrode conductors by a transparent electrode conductor, such as indium tin oxide (ITO), the sensor of the position detecting device of the invention can be superimposed on a display device such as a liquid crystal display. It is obvious that the conductor patterns to configure the first electrode conductors and the second electrode conductors do not need to be formed by a transparent conductor if the sensor is not superimposed on a display device, such as a liquid crystal display.
[0103] It is to be noted that the embodiment of the present disclosure is not limited to the foregoing embodiments, and that various changes can be made without departing from the spirit of the present disclosure.